Kim Kardashian’s little sis, Khloé breaks her silence on the “sad” rumors that Kim Kardashian cheated on her fiance, Kris Humphries.

But despite receiving a cease & desist letter from Kim’s lawyers, Lockett tells TMZ.com that he has emails, text messages and cell phone photos that proves he was intimate with Kim before she announced her engagement to Humphries.

He has yet to produce the evidence.

In an interview with E! News, Khloé slammed New England Patriot Brett Lockett’s wild claims that he cheated with Kim while she was dating Humphries.

“I have…honestly… never heard of him. I think [he’s], crazy,” Khloé told E! News’ Michael Yo at Forbes’ Celebrity 100 celebration last night. “I don’t even know if you know this story,” she asked her husband, Lamar Odom, who responded, “No,” and shook his head.

“It’s so weird that people these days can just say, like complete strangers, ‘Oh my god, he’s been seeing her for five months,’ and this and that, he’s crazy,” Khloé said. “I think it’s very…it’s sad.”

Sadder still: “I think he really believes that he’s been with her.”